On consideration of convenience, wireless keyboard are popularly used with various computing apparatuses, e.g., desk-top computers, notebook computers, personal digital assistants, mobile phones, pocket computers and the like. Specifically, infrared wireless keyboards for use with various computing apparatuses are known. An infrared wireless keyboard simply uses an infrared transmitter in the keyboard and an infrared receiver in a computing apparatuses to establish a link between the keyboard and the computing apparatus. The infrared wireless keyboard does not, of course, need a physical wire connection between the keyboard and the personal computer so that there is no wire clutter.
The infrared wireless keyboard, however, has numerous drawbacks. Specifically, the infrared wireless keyboard requires no obstacle in a path between the infrared transmitter in the keyboard and the infrared receiver in the computing apparatus. Whenever a computing apparatuses has an infrared receiver set on “odd” situation thereof, possibility of establishing transmission path between an infrared transmitter of an infrared wireless keyboard and the infrared receiver of the computing apparatus becomes a criterion to determine whether the wireless keyboard is available or not.
Pocketop Computer Corp. has developed an attachment for an infrared wireless keyboard used with a portable computing apparatus with an infrared receivers set on or near top side thereof. The attachment includes a support and a reflective board engaged to the support. The portable computing apparatus can be positioned substantially erected by leaning itself against the support. In such case, the reflective board can reflect infrared beam emitted from the infrared transmitter to the infrared receiver. However, it is obvious that the solution, provided by Pocketop Computer Corp., is only applied to portable computing apparatuses with infrared receivers set on or near top sides thereof. That is the wireless keyboard of the prior art is not applicable for a portable computing apparatus which has an infrared receiver set on “odd” situations thereof, e.g., waist sides or rear sides.
Gateway 2000, Inc. has utilized various improved configurations for adjusting emitting or receiving direction of an infrared emitted from or to an infrared transceiver set on an electronic apparatus. Details regarding the aforesaid improved configurations have been disclosed in the U.S. Pat. Nos. 6,104,606, 5,978,214, 5,978,213, and 5,781,405. However, it is obvious that the solutions, provided by Gateway 2000, Inc., can not be applied to various computing apparatuses equipped with infrared receivers. Even if an infrared transmitter of a wireless keyboard according to the aforesaid prior arts is capable of adjusting emitting direction of an infrared emitted therefrom, the wireless keyboard is not applicable for a computing apparatus which has an infrared receiver set on “odd” sides thereof.
Therefore, no obstacle in the path and a shorter distance between the transmitter and the receiver constrain the flexibility that user would use a wireless keyboard because an artificial limit is placed on the location and the distance do exist between the infrared wireless keyboard and the computing apparatus. Moreover, the distance between the infrared wireless keyboard and the computing apparatus must not be too great so that the infrared receiver in the computing apparatus cannot detect the infrared beam from the infrared transmitter of the infrared wireless keyboard.
In addition, the infrared wireless keyboard has large power consumption requirements because of the infrared transmitter. The infrared wireless keyboard typically operates on a six-volt power source that is commonly derived from four 1.5-volt batteries. Moreover, the increased power consumption reduces overall battery life so that the batteries must be replaced more often.